In many cases, it is desirable to dry washed food, for example to avoid making watery salad. There are many food-drying devices available. Typically, such device has a container, in which a drying assembly having a plurality of bores, for example a basket, is disposed. The drying assembly can be spun relative to the container. A drive mechanism for spinning the drying assembly relative to the container is provided, while the drive mechanism is usually integrated with the cover of the container. The drive mechanism is typically actuated by a handle.
Salad spinners in US2010/0263555A1 provide different handle rotation speeds limited by different gear ratios. Specifically, when the drive mechanism of the spinners in this US publication is driven by the handle rotating in clockwise direction, the handle engages a set of gear system such that rotation speed is amplified by one given gear ratio. When the handle rotates in anti-clockwise direction, the handle engages another set of gear system with which the rotation speed is amplified by a different gear ratio. In principle, however, there is no difference between these devices with any other salad spinners that are basically being driven at one speed amplification by a given gear ratio at one given single operation.
It is desirable to devise an intelligent drive mechanism that can start the motion at a lower speed amplification (hence less effort) at/or above a predetermined threshold load and is then capable to shift to a higher speed amplification automatically to improve the performance of the operation of food-drying devices.